front-pad a number with zero's

Replies are listed 'Best First'.
Re: front-pad a number with zero's by japhy (Canon) on Oct 30, 2001 at 23:27 UTC
That's broken, due to the use of the string comparison operators (like `lt`) in the place of numerical comparison operators (like `<`). Also, a while loop can be replaced with math: `$string = ('0' x ($wanted - $current)) . $string;` [download] But honestly, this is a job for `sprintf()`: `sprintf "%0${len}d", $number;` [download] That is, `sprintf("%05d", 123)` returns `00123`. _____________________________________________________ Jeff`[japhy]`Pinyan: Perl, regex, and perl hacker. `s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;`	[reply] [d/l] [select]
Re^2: front-pad a number with zero's by Anonymous Monk on Jun 13, 2008 at 08:40 UTC
You are a genius! Where did you get this sprintf "%0${len}d", $number; It's saved me a lot of troubles. 06-13-2008 Thank you.	[reply]
Re^3: front-pad a number with zero's by andreas1234567 (Vicar) on Jun 13, 2008 at 09:27 UTC
Where did you get this sprintf "%0${len}d", $number; The sprintf documentation, perhaps? `printf '<%06s>', 12; # prints "<000012>"` [download] BTW: The thread you responded to is 7 years old. -- No matter how great and destructive your problems may seem now, remember, you've probably only seen the tip of them. [1]	[reply] [d/l]
Re^4: front-pad a number with zero's by Anonymous Monk on Aug 27, 2011 at 01:35 UTC
Re: front-pad a number with zero's by Masem (Monsignor) on Oct 30, 2001 at 23:27 UTC
Why not (simply)?: `$string = sprintf( "%05d", $number );` [download] ----------------------------------------------------- Dr. Michael K. Neylon - mneylon-pm@masemware.com \|\| "You've left the lens cap of your mind on again, Pinky" - The Brain "I can see my house from here!" It's not what you know, but knowing how to find it if you don't know that's important	[reply] [d/l]
(tye)Re: front-pad a number with zero's by tye (Sage) on Oct 31, 2001 at 00:18 UTC
To both pad short values and (left)truncate long ones: `$str= substr("0"x$len.$str,-$len);` is another WTDI. - tye (but my friends call me "Tye")	[reply] [d/l]
Re: front-pad a number with zero's by lhoward (Vicar) on Oct 30, 2001 at 23:27 UTC
You can do the same thing with sprintf. `my $f=sprintf("%05d",123);` [download] will put "00123" into $f.	[reply] [d/l]
(Ovid) Re: front-pad a number with zero's by Ovid (Cardinal) on Oct 30, 2001 at 23:29 UTC
TIMTOWTDI (though sprintf is faster): `sub pad_zeros { my $optimal_length = 5; my $num = shift; $num =~s/^(\d+)$/("0"x($optimal_length-length$1)).$1/e; return $num; }` [download] Cheers, Ovid Join the Perlmonks Setiathome Group or just click on the the link and check out our stats.	[reply] [d/l]
Re: (Ovid) Re: front-pad a number with zero's by japhy (Canon) on Oct 30, 2001 at 23:32 UTC
A regex is overkill here. (If I'm saying it, trust me...) If you're against using `sprintf()`, just do the math: `sub pad { my ($num, $len) = @_; return '0' x ($len - length $num) . $num; }` [download] _____________________________________________________ Jeff`[japhy]`Pinyan: Perl, regex, and perl hacker. `s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;`	[reply] [d/l]


Perl: the Markov chain saw
	PerlMonks